To operate a typical controller for various electric appliances, information devices, indoor or outdoor equipment or the like, a user need to directly touch the controller. Specifically, a user needs to perform operations such as pressing, turning or moving buttons, icons or the like on a controller equipped with such buttons, icons or the like.
A remote control for remotely operating equipment allows a user to operate the equipment to be operated without directly touching the equipment. However, the user needs to directly touch the remote control equipped with buttons, icons, or the like to operate the remote control.
In board games such as go, shogi, and chess, a game clock is used for measuring the time each player takes for considering a move. A controller for a game clock is a device including buttons or the like to be directly touched by the players. In a game, each player needs to operate by directly touching a button or the like on the controller every time the player completes a move (which refers to placing a go stone on the game board or moving a go stone, a shogi or chess piece or the like on the game board). The time one player takes for considering a move is the time that elapses between the operation performed by the other player and the next operation performed by the former.
As a type of controller that is operated without a user's direct touch, a controller using a motion sensor is known. When the controller detects a motion of a person in the room, the controller turns on; when the controller no longer detects a motion, the controller turns off. However, controlling by a controller of this type is limited to the simple on-off operation controls of equipment such as lighting equipment.
A method has been proposed in the technical field of digital camera in which a built-in controller of a camera analyzes an image captured with an image sensor and, when the controller recognizes a predetermined shape, the controller performs a predetermined operation control. Specifically, a shape formed by a user with a hand and fingers (hereinafter referred to as a finger pose) within an image capturing range is set in a controller as a cue sign for initiating a predetermined operation. However, the method has a problem concerning an appropriate selection of a finger pose and a problem that quick recognition and avoidance of false recognition cannot be achieved at the same time. Patent Literature 1 described below discloses a technique using such a method.